Return-Path: Received: from mtain-da10.r1000.mx.aol.com (mtain-da10.r1000.mx.aol.com [172.29.64.82]) by air-ma08.mail.aol.com (v127_r1.1) with ESMTP id MAILINMA084-b5334b89c3c9d3; Sat, 27 Feb 2010 20:15:53 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-da10.r1000.mx.aol.com (Internet Inbound) with ESMTP id 47FA0380000AB; Sat, 27 Feb 2010 20:15:52 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NlXjf-0005P5-Pf for rs_out_1@blacksheep.org; Sun, 28 Feb 2010 01:14:19 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NlXjf-0005Ow-4l for rsgb_lf_group@blacksheep.org; Sun, 28 Feb 2010 01:14:19 +0000 Received: from blu0-omc1-s10.blu0.hotmail.com ([65.55.116.21]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NlXjd-0007lF-5M for rsgb_lf_group@blacksheep.org; Sun, 28 Feb 2010 01:14:19 +0000 Received: from BLU146-W29 ([65.55.116.9]) by blu0-omc1-s10.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.3959); Sat, 27 Feb 2010 17:14:09 -0800 Message-ID: X-Originating-IP: [216.137.216.198] From: Laurence KL1X To: Date: Sat, 27 Feb 2010 16:14:08 -0900 Importance: Normal In-Reply-To: <55A21536-8446-4BA1-82E6-0E42D39033D6@leeds.ac.uk> References: ,<91FFB5D65F3547FFA086D396DBFAEFA7@White>,<55A21536-8446-4BA1-82E6-0E42D39033D6@leeds.ac.uk> MIME-Version: 1.0 X-OriginalArrivalTime: 28 Feb 2010 01:14:09.0734 (UTC) FILETIME=[54A30660:01CAB813] X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Content-Type: multipart/alternative; boundary="_35d7ee0e-038a-4eb9-8305-731163d1b004_" Subject: RE: LF: Loran A and C X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=FORGED_HOTMAIL_RCVD, HTML_MESSAGE autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G x-aol-sid: 3039ac1d40524b89c3c87587 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --_35d7ee0e-038a-4eb9-8305-731163d1b004_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Chris Markus et al thanks - I did another middle of the day recording usi= ng an omni eprobe -=20 =20 http://kl1x.com/alaskaloran0042z.wav 28th Feb 10 - Excuse some of the com= mon mode noise burbles.=20 =20 Unfortuately I leave for Oklahoma in a few hours so this will be it for a= while =20 Laurence WE2 xpq kl1X G4dma =20 > From: C.Trayner@leeds.ac.uk > To: rsgb_lf_group@blacksheep.org > Date: Sat, 20 Feb 2010 11:21:05 +0000 > Subject: Re: LF: Loran A and C >=20 > Dear Markus, Lawrence and others, >=20 >=20 > Thanks for your interesting comments on this theme. >=20 > > The slow phasing effect is caused by pulsegroups of these very similar= rates, walking through one another in time. >=20 > I think I can hear two effects which might be described as phasing. >=20 > One is due to the different GRIs (Group Repetition Intervals, i.e. pulse= group rates) which Markus describes. This appears a a change in the chitt= ering sound. When the groups coincide you hear it as "chit chit chit" and= the pulsiness is more pronounced: you can hear this about 1/5 to 1/4 of= the way through the recording. When they fit in each others' gaps you hea= r "chitchitchit" and the sound seems smoother: you can hear this just befo= re half way through the recording. >=20 > The other effect is a change in the relative strengths of higher and low= er audio frequencies. You can hear this from about 4/5 of the way through= to nearly the end, where the sound cycles between treble and bass. Presum= ably this is cancellation in some part of the 90-110 kHz spectrum, though= the treble will be represented by both the parts just above 90kHz and tho= se just below 110 kHz, so presumably it is subtler than that*. Maybe this= is caused by frequency-selective fading, presumably what Lawrence describ= ed as the "musical sounds they made as sky waves did their thing". Could= someone more knowledgable than me comment on that? >=20 > * Unless Lawrence was demodulating as SSB, in which case he would see on= ly one half of the spectrum. >=20 >=20 > For those who have deleted the original message, the recording is at > > http://kl1x.com/loranalaska.wav >=20 >=20 > 73, > Chris G4OKW >=20 > ----------------------- > Dr Chris Trayner > School of Electronic & Electrical Engineering, > The University of Leeds, > Leeds LS2 9JT, United Kingdom > Tel: +44 113 34 32053 > Fax: +44 113 34 32032 >=20 >=20 >=20 =20 _________________________________________________________________ Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. http://clk.atdmt.com/GBL/go/201469229/direct/01/=3D --_35d7ee0e-038a-4eb9-8305-731163d1b004_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Chris  Markus et al thanks - I did another middle of the day rec= ording using an omni eprobe -
 
http://kl1x.com/alaskalor= an0042z.wav  28th Feb 10 - Excuse some of the common mode noise= burbles. 
 
Unfortuately I leave for Oklahoma in a few hours so this will be it= for a while
 
Laurence WE2 xpq  kl1X  G4dma
 
> From: C.Tra= yner@leeds.ac.uk
> To: rsgb_lf_group@blacksheep.org
> Date: Sa= t, 20 Feb 2010 11:21:05 +0000
> Subject: Re: LF: Loran A and C
&g= t;
> Dear Markus, Lawrence and others,
>
>
> Th= anks for your interesting comments on this theme.
>
> > Th= e slow phasing effect is caused by pulsegroups of these very similar rates= , walking through one another in time.
>
> I think I can hear= two effects which might be described as phasing.
>
> One is= due to the different GRIs (Group Repetition Intervals, i.e. pulse group= rates) which Markus describes. This appears a a change in the chittering= sound. When the groups coincide you hear it as "chit chit chit" and the= pulsiness is more pronounced: you can hear this about 1/5 to 1/4 of the= way through the recording. When they fit in each others' gaps you hear "c= hitchitchit" and the sound seems smoother: you can hear this just before= half way through the recording.
>
> The other effect is a ch= ange in the relative strengths of higher and lower audio frequencies. You= can hear this from about 4/5 of the way through to nearly the end, where= the sound cycles between treble and bass. Presumably this is cancellation= in some part of the 90-110 kHz spectrum, though the treble will be repres= ented by both the parts just above 90kHz and those just below 110 kHz, so= presumably it is subtler than that*. Maybe this is caused by frequency-se= lective fading, presumably what Lawrence described as the "musical sounds= they made as sky waves did their thing". Could someone more knowledgable= than me comment on that?
>
> * Unless Lawrence was demodulat= ing as SSB, in which case he would see only one half of the spectrum.
&= gt;
>
> For those who have deleted the original message, the= recording is at
> > http://kl1x.com/loranalaska.wav
>
= >
> 73,
> Chris G4OKW
>
> -------------------= ----
> Dr Chris Trayner
> School of Electronic & Electrica= l Engineering,
> The University of Leeds,
> Leeds LS2 9JT, Uni= ted Kingdom
> Tel: +44 113 34 32053
> Fax: +44 113 34 32032>
>
>

Your E-mail= and More On-the-Go. Get Windows Live Hotmail Free. Sign up now. =3D --_35d7ee0e-038a-4eb9-8305-731163d1b004_--